In 2012, the Seahawks ran the ball more than any other NFL team - 536 times, for an average of 33.5 attempts per game.
Seattle finished 3rd in the NFL with 4.8 yards per rushing attempt and 3rd in yards per game at a 161.2 yard clip. They tied 9th for rushing TDs with 16. Their 14 runs of 20+ yards finished tied for 7th in the NFL.
In Seattle's two Playoffs games, they rushed 65 times for 347 yards, a 5.3 ypc clip and 173.5 yards per game.
In pass protection, they gave up 33 sacks - 12th least in the NFL - and 64 QB hits, which finished 6th in the NFL, though those numbers are indeed skewed by the amount Seattle runs. Note that according to Football Outsiders' Adjusted Sack Rate, Seattle was mediocre - 20th in the NFL with a 7.2% sack rate - this metric takes into account sacks (plus intentional grounding penalties) per pass attempt adjusted for down, distance, and opponent.
These are definitely impressive numbers taken as a whole though, regardless, and are likely a big reason that both Russell Okung and Max Unger ended up as starters in the Pro Bowl. They're impressive for the offensive line unit as a whole though, more so considering Seattle had nearly the worst continuity at that position in the NFL in 2012, according to Football Outsiders' measure.
Continuity along the offensive line is extremely important - you're working as a unit, making last minute changes in the heat of battle and adjusting to defensive changes on the fly up to 60 or 70 times a game. Continuity is important because it eases communication, establishes comfort between linemates to know where their cohort is going to be on any given situation, and it even helps with some of the more abstract concepts like camaraderie and synergy. Continuity on the O-Line is arguably as important (or more important) than chemistry between quarterback and receiver.
Back in January, Max Unger brought all this up in an interview:
"Our (meeting) room has really come together this year," Unger said. "What we're doing in there seems to be working pretty well. There's obviously a lot of room for improvement, but kind of getting the same guys to start the majority of the games together is really a step in the right direction."
It's funny that Unger says that, because while it may have seemed true that Seattle was going in the right direction (obviously having more success, anyway), the continuity hadn't really improved. According to FO's tracking, Seattle started 8 different players on the OL and had 9 different lineups throughout the year.
The longest stretch where the same five players started in the same five spots on the offensive line was three games. Three games! Injuries on the OL are inevitable, but damn! Somehow, this was worse than even the 2011 season.
Now, note that there is a difference between 'line combinations' and 'line changes'. The FO continuity score is more focused on game-to-game flow than aggregate numbers of line combinations used, I believe. When you get into the total number of 'line combinations' that Seattle used, it's not as bad as prior years, but taking into account the number of line changes as the season went on - McQuistan moving to and fro, James Carpenter in and out, the interminable J.R. Sweezy/John Moffitt time-share - it's amazing they could have much success at all. The bottom line is that the offensive line, over the last few seasons, has been a patchwork quilt blanket, as relative to the rest of the NFL. As Clare Farnsworth pointed out in January:
This season, the Seahawks have used eight starters in five different combinations - with Giacomini, Unger and McQuistan making all the starts and Okung making 15. Last year, it was eight starters in six combinations - with none of the linemen making all 16 starts, and three players starting at left guard and also right guard. In 2010, Carroll's first season, it was nine starters in 10 combinations - with four starters at left guard and three each at left tackle and right guard. In 2009, Jim Mora's only season as coach, it was 10 starters in seven combinations - with four starters at left tackle and three each at left guard and center. In 2008, Mike Holmgren's final season as coach, it was 10 starters in eight combinations - with four starters at right guard and three at left tackle.
I think any offensive lineman would tell you that it's very important to log flight hours next to the guy(s) he'll be playing with in the games - and I'm not even talking 'playing on the same offensive line' but literally 'playing next to him'. With all the movement last year in Seattle's platoon system due to injuries, it just makes their top-tier numbers in the run game and mid-range numbers in pass pro that much more impressive. Imagine what Tom Cable's line could do if they actually did end up with some continuity this season. First off, I would bet that the pass protection improves drastically this season if the Hawks can somehow manage to sustain a little continuity on the line, but what should be even more interesting is how much improved Seattle's run game can become.